To cook, or not to cook, that is the question.

Fad diets are no new player in the weight loss scene (the Atkins diet was originally written in the 70’s!), but this sure doesn’t mean that they’ve lost any steam. From the HCG Diet to South Beach, a vast spectrum of ways to transform your current physique from “flab” to “FAB” have been proposed. While some have gained sound reputations for achieving that beach body with healthy eating habits, others have the potential to be downright dangerous. One particular food fashion that has swept the masses in recent years suggests that you’ll never have to cook again. Intrigued? Skeptical? Crying tears of joy? Ready for the raw details?

You can thank Maximillian Bircher-Benner for the Raw Food Diet, which requires that all food consumed is never heated above 115-118 degrees Fahrenheit (adios stove!). Many raw foodists are also vegetarian or vegan, but some individuals do consume raw animal products, including raw eggs, fish, meat, and milk (unpasteurized). They mainly tend to chow on high amounts of fruits, vegetables, sprouts, seeds, and grains, while generally steering clear of caffeine, alcohol, and added sugars. No gimmicks and no miracle pills required, it sounds like this “diet” could get you on the fast track to health that will actually last – or will it?

Science has begun to question whether raw food truly trumps a cooked cuisine. Could untouched earthen fare provide more nutritional benefit than it’s steamed, sautéed, or baked counterpart? Followers say that their main reasons for adapting to a raw diet are to maintain health, prevent illness, and to live in a natural and healthy way for a long time (cheers to that!). Some of the experts have set out to see if a raw diet can really accomplish these characteristics of seemingly perfect health. So before you go all raw, you should consider what the research has to say.

The Pac-Man Raw Foodist – Image courtesy of photopin.com

Macronutrient Distribution

The Institute of Medicine (IOM) recommends that all healthy human eaters consume a range of carbohydrates, proteins, and fats in a daily diet. Based on their recommendations, we should be taking in around 45-65% of a day’s calories as carbohydrates, 10-35% as protein, and 25-35% as healthy fat. Raw foodists appear to be right on track, consuming around 60% carbs, 30% fat, and 10% protein. The raw way is off to a good start so far, but let’s check out the nitty gritty on nutrients.

VIT B12

Vitamin B12 is crucial for a plethora of physiological functions that keep the body running like a well-oiled machine. Deficiency of B12 has been flagged as a risk factor for heart disease, making it an important nutrient for analysis of diet. The interest in B12 status among strict raw foodies, stems from the fact that this vitamin has only been proven to be absorbed in its active form from animal sources. Although the diet guidelines do not prohibit raw meat, studies show that most dieters consume little (if any). Koebnick et al. recruited around 200 humans that followed a long-term diet consisting of 70-100% raw food – 38% of these individuals were Vitamin B12 deficient. In addition, the lowest levels were associated with the lower consumptions of food with animal origin.

TAKEAWAY: This seems to be more of an herbivore vs. carnivore debate, than raw vs. cooked. Nonetheless, if you’re considering a raw diet, you should be aware of the possibility of B12 deficiency depending on the meatiness of your diet. Consider consuming some high B12 sources (clams, oysters, meats, etc.) or consulting a doctor about whether B12 supplementation is appropriate for your individual nutrition needs.

Carotenoids: Beta-Carotene and Lycopene

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Carotenoids are nutritional components known for their powerhouse role in reducing the risk for chronic diseases, such as heart disease, prostate and lung cancer, and macular degeneration (loss of vision). You can usually find them in the red and orange varieties of veggies and fruits (carrots, sweet potato, red pepper, etc.), as well as broccoli, spinach, and black-eyed peas. It has been suggested that cooking and processing methods can increase the amount of beta-carotene and lycopene that can be absorbed and functionally utilized in our body (aka bioavailability). If this is the case, a raw diet could potentially decrease the bioavailability of these crucial nutrients. Garcia et al. measured the carotenoid plasma levels of around 200 long-term raw foodians and found that 63% of them had beta-carotene levels associated with chronic disease prevention. These levels increased with increasing consumption of beta-carotene sources, suggesting that high intake of this nutrient may be enough to overcome any properties in the raw form that reduce absorption. Lycopene did not fare as well in its raw state – 77% of subjects had plasma levels below the average reference level for healthy populations.

TAKEAWAY: Raw and cooked split the field on this one. You may want to consider cooking foods that contain lycopene (tomatoes!) to get the full benefit of this healthful compound. If you’re going 100% raw, try adding some reds and oranges to your plate to increase your beta-carotene levels.

LDL and HDL Cholesterol

Elevated LDL (bad) cholesterol and low HDL (good) cholesterol levels are associated with increased risk of heart disease. Too much LDL can build up in arteries and form plaque that could eventually lead to a blockage – hence the name “bad” cholesterol. Koebnick and friends (mentioned above) also found that those who stuck to a long-term raw food diet had lower LDL cholesterol, but 46% also had lower HDL cholesterol (lowest levels were in those that ate the most raw food).

TAKEAWAY: Although lower LDL levels are definitely worthy of a high-five, the study suggests that greater consumption of raw food does not have a positive impact on “good” HDL cholesterol. A concern in raw food diets may be a lack of nutrients that do increase HDL – omega-3 fatty acids from fish and shellfish (aka EPA) are thought to be players in upping this type of cholesterol. If these foods aren’t on your personal menu, you could consider speaking with a doctor about fish oil supplementation.

Body Mass Index (BMI) and Amenhorrea

Body mass index is often used to classify individuals as underweight, normal, overweight, or obese, in order to better determine health and disease risks. Amenorrhea is the cessation of menstruation often times preceded by a sudden and drastic loss of weight. The Giessen Study looked at 216 men and 297 women who consumed various levels of raw food diets and examined the relationship of their eating habits with body weight loss, underweight, and amenorrhea. The results showed that 73.8% of the participants had a normal body weight. In addition, they evaluated their data and calculated that people on a strict raw food plan were 3 times more likely to become underweight and women were 7 times more likely to experience amenorrhea.

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TAKEAWAY:The Raw Food Diet definitely appears to be effective for weight loss, but it also appears to increase the risk for becoming underweight and experiencing amenorrhea. Because such a large portion of the diet is fruits and vegetables (two thumbs up), the limited amount of energy dense foods consumed may contribute to a lower caloric intake. Anyone who chooses to follow this (or any) diet, should ensure that they are consuming enough food to meet the body’s energy requirements for adequate function (this may mean eating even more nutrilicious fruits and veggies).

So you’ve made it through most of the ups and downs of the raw food way! Hopefully you’ve taken away not only valuable information about raw foodism, but a sense of how to evaluate every diet that you consider. Each and every person’s nutritional needs are unique and generally there is no “one size fits all” diet plan. It may take a little mixing and matching (raw and cooked, perhaps?), but it is well worth the investment to establish eating habits that optimize your individual health.

Related

Nice article! A good addition would be if you could also address the claims that that raw foodists make about enzymes (that cooking destroys these enzymes that are necessary for good digestion and health).

Great suggestion Sheila! It is true that some methods of cooking can “leech” out some of the minerals in nutrient-rich foods (a big part of the reason to go raw). Certain components of foods, aside from lycopene, also benefit from cooking (ex: oxalic acid in spinach binds to calcium and prevents absorption, but when you steam or boil the spinach, this doesn’t occur). You can actually recover those leeched nutrients by using the water from boiling or steaming to cook rice or other grains.

These details are, in my opinion, why it may be best to have a mixed diet – to make sure that you’re getting the most out of your food! This piece could definitely have a follow-up on the foods and nutrients that are either positively or negatively affected by cooking. Thanks for reading!

Great post, Ann! I personally feel that the raw food diet is pretty extreme. I’m glad to see that you looked into the research on it.

A couple minor thoughts: 1) B12–the most important consequences of deficiency include megaloblastic anemia and neurologic complications (not just risk of CVD).
2) So minor–but I’m pretty sure the DASH diet is not a fad diet, nor intended for weight loss per se.

You’re definitely right Lola! DASH is not quite “fad”. My initial intention was tk use it as a representative diet that has been given a “sound reputation”. It’s definitely a little confusing that I paired it with the others..thanks for pointing that out, as well as the other issues that could arise from Vit B12 deficiency.

With the horrible results of individuals eating under cooked meat or eggs would help me to put the skids on the raw diet. Your blog covers the subject very objectively and with a vocab the general public can, shall I say without pun intended, easily digested?

Very nice play on words Virginia!! You have a great point – there is a risk of eating raw meat, which is definitely something that people should be aware of, if they choose to do so. Thanks for your comment!

While I am not a vegan’vegetarian, several family members are. I am glad to read your article and to have some good food for thought when discussions re diet occur. Timely topic in this diet concious era. Thanks.

Thanks for reading Mary and I’m glad I could provide some table topics for you and your family :). If anyone is going to follow an extreme diet (such as 100% raw), there is without a doubt extra effort to apply to make sure it is done in a healthy way. It would be interesting to hear what your friends and family members do to ensure this!

Hi Angela – thank you for sharing this article! Extremely interesting stuff, especially how they are addressing both natural and additive colorings. I’d like to find more literature on the topic to see what other people have found in their research. Nutrition is such a new science, it seems as though findings are emerging daily!

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About Mind The Science Gap

Mind The Science Gap was a Science Communication Training blog that ran between 2012 - 2013.

Each semester, ten Master of Public Health students from the University of Michigan participated in a course on Communicating Science through Social Media. Each student on the course was required to post weekly articles here as they learned how to translate complex science into something a broad audience can understand and appreciate. And in doing so they were evaluated in the most brutal way possible - by the audience they were writing for!